Re: [PATCH net 1/2] veth: keep carrier off when resizing channels with a down peer

[Xia Yan]

Hi,

Resending as plain text because the mailing lists rejected my previous
reply for containing HTML.

This issue was found during LLM-assisted source review of
veth_set_channels(). I reproduced it with a veth pair in a network
namespace by bringing one end up, leaving the peer down, and changing
the active end's RX/TX channel counts with ethtool -L. The UP endpoint
then incorrectly reported LOWER_UP.

I built and booted unpatched and patched UML kernels and ran the
accompanying selftest. The four mixed up/down cases fail before the
fix; all eight cases pass after the fix.

I will include the discovery method in the commit message if another
revision is needed.

Thanks,
Xia Yan